title: Palladium-catalyzed direct alkenylation of 2-oxazolones: an entry to 3,4,5-trisubstituted 2-oxazolones.
abstract: Described herein is a novel method for the synthesis of 3,4,5-trisubstituted 2-oxazolones featuring the first Pd-catalyzed dehydrogenative alkenylation of 2-oxazolones, which is realized by employing 10 mol % of Pd(OAc)2 as the catalyst and the use of readily available Cu(OAc)2 as the oxidant. A wide range of functional groups, such as F, Cl, Br, OMe, ester, ketone, amide, alkyl, and aryl substituents, are found to be compatible under the reaction conditions. The utilization of the C-H functionalization strategy provides a straightforward, convenient, and highly atom-economical approach for the construction of 3,4,5-trisubstituted 2-oxazolones. It is worth noting that the 4-alkenyl 2-oxazolones can be smoothly converted into naphtho[1,2-d]oxazol-2-ones via a photochemical transformation.
authors.affiliation: Department of Chemistry, Zhejiang Normal University , 688 Yingbin Road, Jinhua 321004, People's Republic of China.
authors.forename: Zenghui
authors.initials: Z
authors.lastname: Lu
authors.forename: Fang
authors.initials: F
authors.lastname: Luo
authors.forename: Lina
authors.initials: L
authors.lastname: Wang
authors.forename: Gangguo
authors.initials: G
authors.lastname: Zhu